1. Field of the Invention
The present invention relates to a method for controlling operation of a refrigerator, and, more particularly, to a method for controlling operation of a refrigerator capable of reducing electricity consumption by controlling a refrigerant passage switching valve after operation of a compressor stops.
2. Description of the Related Art
In general, a refrigerator is an appliance operating according to a refrigeration cycle that circulates a refrigerant into the refrigerator. The refrigerator is used to store various foods in a fresh state for a long time by providing cold air, produced by absorption of surrounding heat generated during evaporation of a liquid-state refrigerant, into food storage chambers, such as a freezing chamber and refrigerating chamber thereof. Such a refrigerator lately is increasing in size and capacity to store a large amount of foods.
A cooling system, employed in the refrigeration cycle, includes: a compressor to compress a refrigerant into a high-temperature and high-pressure state; a condenser to condense the compressed refrigerant through heat exchange with surrounding air; capillary tubes to expand the condensed refrigerant to a low pressure state; and a freezing chamber evaporator and refrigerating chamber evaporator to evaporate the expanded low-pressure refrigerant through heat exchange with foods stored in the refrigerator.
The freezing chamber evaporator and refrigerating chamber evaporator are installed in a freezing chamber and refrigerating chamber, respectively, to enable independent cooling of both the chambers.
Such a cooling system further includes: a refrigerant passage switching valve, which switches refrigerant passages to selectively or simultaneously supply the refrigerant, passed through the condenser, to the freezing chamber evaporator and/or the refrigerating chamber evaporator; and a freezing chamber fan and refrigerating chamber fan, which circulate the cold air, passed through the freezing chamber evaporator and refrigerating chamber evaporator, throughout the freezing chamber and refrigerating chamber, respectively.
In the above described refrigerator, the compressor starts to operate after a temperature of the freezing chamber or refrigerating chamber rises beyond an associated preset temperature. A conventional operation control pattern of the refrigerator will be explained with reference to FIG. 1.
Upon operation of the compressor, the refrigerating chamber fan and the freezing chamber fan are driven simultaneously, and the refrigerant passage switching valve is controlled to discharge the refrigerant to only the refrigerating chamber until the temperature of the refrigerating chamber drops less than the associated preset temperature, i.e. refrigerating chamber preset temperature.
If the temperature of the refrigerating chamber drops less than the refrigerating chamber preset temperature, the refrigerant passage switching valve is controlled to discharge the refrigerant to only the freezing chamber while preventing the refrigerant from entering the refrigerating chamber. In this case, the refrigerating chamber fan is further driven only for a predetermined time sufficient to perform a high-humidity maintenance control operation (i.e. defrosting using a valve) of the refrigerating chamber that circulates the cold air, absorbing frost or dew generated on the refrigerating chamber evaporator, in the refrigerator.
If the temperature of the freezing chamber drops less than the associated preset temperature, i.e. freezing chamber preset temperature, the refrigerating chamber fan is again operated for a predetermined time as the operation of the compressor stops, and the refrigerant passage switching valve is controlled to discharge the refrigerant to only the refrigerating chamber.
Once the operation of the refrigerating chamber fan stops after the lapse of the predetermined time, the refrigerant passage switching valve is controlled to discharge the refrigerant to both the refrigerating chamber and the freezing chamber, achieving pressure balance of the refrigerant passages. Such a refrigerator operation control routine is repeated while checking whether or not the temperature of the refrigerating chamber or freezing chamber rises beyond the associated preset temperature.
However, the conventional operation control pattern has a problem in that, although the refrigerant passage switching valve is readily opened to the refrigerating chamber and freezing chamber after the operation of the compressor stops to thereby achieve rapid pressure balance of the refrigerant passages, the refrigerant flows from a high-pressure side to a low-pressure side, causing rising of the temperatures of the refrigerating chamber and freezing chamber and resulting in an increase of electricity consumption due to an increased operational load.
Further, the high-humidity maintenance control operation of the refrigerating chamber, which is obtained by further driving the refrigerating chamber fan for the predetermined time while directing the refrigerant into the freezing chamber after completing temperature control of the refrigerating chamber, achieves only minor humidification effects even if the refrigerating chamber fan is driven to blow the frost generated on the refrigerating chamber evaporator into the refrigerator, since a temperature of the refrigerating chamber evaporator is kept at a sub-zero temperature, i.e. a temperature of approximately −15° C.